Hi,
Buy the lense. You won't regret it. Alaska is really beautiful. I have been to Anchorage many times for work trips. The scenery is absolutely stunning. The lense will work well. Imagine if you don't get it, you won't be able to capture all the beautiful scenes. But if you do buy it and then decide to sell it later, at least you would have managed to capture all that stunning beauty around you. Try to do more of your travelling early before summer comes, that's when it gets really busy and all the tourist come. Off peak season is nice and quite,probably cheaper too. When you get out of the airport in Anchorage you will see one of the biggest, if not the biggest 'carparks' full of light aircraft. You can actually rent a bicycle and cycle around. It's great. In summer go down to the rivers and watch the locals fish for salmon. Loads of them. The rivers actually look 'red' if you fly from above because of all the fish. It is almost like going to a fish farm. You can get great pics of people fishing. Pop into F street station for makan, that's my usual joint. Try the beer battered halibut. It's on F street around the corner from Hilton. The waitresses are really friendly and some are really gorgeous too. You can try reindeer sausages as well on the corner stands around the city. Have fun, you will enjoy it there I am sure, unless you are not the outdoor sort. So much to do....................... if you decide to go tracking in summer becareful of bears. Ask the locals, they can give you good advice on what to do and what not. Hope that helps a bit. I am sure you will love it.